You and the other players (or CPUs) race on rainbow-colored rails. By pressing the "A" button when you are on a rail to to grind the rails and get speed. If you are on a black rail you can not grind by pressing the "A" button until you pass the black rail. If you accidentally press the "A" button on the black rail Kirby will loose speed and a icon of a "!" will appear above Kirby's head. If you grind by pressing the "A" button on the end of a black strip with the correct timing Kirby will get a boost witch is greater depending on the timing accuracy.